Engine cylinder head intake port configuration

ABSTRACT

A cylinder head for an internal combustion engine is disclosed having an intake port geometry configured to reduce fuel puddling and improve fuel atomization. The cylinder head includes a housing having a recess defining a top portion of a combustion chamber. The cylinder head further includes intake and exhaust ports defined by channels extending from the top portion of the combustion chamber to an outer end of the housing. An intake valve is positioned within the cylinder head to control communication of the intake port with the combustion chamber, and an exhaust valve is positioned within the cylinder head to control communication of the exhaust port with the combustion chamber. The intake port further includes a cross-section having a modified D-shape with a single 90 degree corner. The modified D-shape cross-section extends substantially a length of the intake port.

BACKGROUND OF THE INVENTION

Embodiments of the invention relate generally to cylinder head intakeport configuration for internal combustion engines and, moreparticularly, to intake port geometry configured to reduce fuel puddlingand improve fuel atomization.

Puddling of fuel in an intake passage of an internal combustion engineleads to several undesirable conditions. Fuel puddling occurs when anengine is shut down or is run at very low speeds. In these conditions,the air stream within the intake manifold lacks sufficient velocity andturbulences to keep fuel in suspension. As a result, liquid fuel tendsto settle out and collect in low areas of the intake.

When running at low speeds, liquid fuel present in the intake port maydrain into the combustion chamber through the intake valve. When airstream velocity in the intake manifold increases due to acceleration,the fuel puddles are drawn into the combustion chamber and results inexcess fuel present during combustion, which leads to incompletecombustion resulting in a surge of black smoke in the exhaust orbackfiring through the carburetor. When fuel puddles in the intake aftershut down, upon start up, the result is an overly rich air/fuel mixturethat can result in misfires and audible pops.

The combustion process could be improved if the air/fuel mixture wasmore consistent upon start up and acceleration. A more consistentmixture will result if the evaporation rate within the intake port isincreased because less liquid fuel will be present. The increasedatomization will result in improved combustion and more consistentexhaust emissions.

Some engines may have modified intake port geometry to reduce fuelpuddling and improve atomization. For instance, the intake port mayprovide for liquid fuel to drain into a high turbulent region created bya ridge or a bump. The turbulence will increase atomization of theliquid fuel and improve the air/fuel mixture. However, engines are oftendesired to operate in more than one orientation. Accordingly, liquidfuel may not properly drain into the turbulent region when the engineoperates in a second orientation.

Therefore, it would be desirable to design a cylinder head for aninternal combustion engine with an intake port to reduce fuel puddling.Also, it would be desirable to have an intake port geometry that wouldimprove fuel atomization. It would be further advantageous if an enginecould reduce fuel puddling and improve atomization when the engine isconfigurable for operation in different orientations.

BRIEF DESCRIPTION OF THE INVENTION

The invention relates generally to a cylinder head intake port geometryfor an internal combustion engine configured to reduce fuel puddling andimprove fuel atomization.

In accordance with one aspect of the invention, a cylinder head for aninternal combustion engine includes a housing having a recess defining atop portion of a combustion chamber. The cylinder head further includesan intake port defined by a first channel extending from the top portionof the combustion chamber to an outer end of the housing, and an exhaustport defined by a second channel extending from the top portion of thecombustion chamber to an outer end of the housing. An intake valve ispositioned within the cylinder head to control communication of theintake port with the combustion chamber, and an exhaust valve ispositioned within the cylinder head to control communication of theexhaust port with the combustion chamber. The intake port furtherincludes a cross-section having a modified D-shape with a single 90degree corner. The modified D-shape cross-section extends substantiallya length of the intake port.

In accordance with another aspect of the invention, an internalcombustion engine is configured to operate in a horizontal and avertical crankshaft configuration. The engine includes a cylinder blockhaving at least one cavity defining a combustion chamber, a crankshaftrotatably mounted to cylinder block, and at least one piston moveablyinserted in the cylinder block cavity. At least one cylinder head ismounted to the cylinder block to enclose the combustion chamber. Thecylinder head includes an intake port defined by a first passage incommunication with the combustion chamber, the intake port having firstand second flat planar surfaces and an exhaust port defined by a secondpassage in communication with the combustion chamber. An intake valve ispositioned to control communication of the intake port with thecombustion chamber and an exhaust valve is positioned to controlcommunication of the exhaust port with the combustion chamber. The firstflat surface of the intake port has a cross-section that issubstantially horizontal when the engine is positioned in a firstorientation where the crankshaft is substantially horizontally oriented,while the second flat surface of the intake port has a cross-sectionthat is substantially horizontal when the engine is positioned in asecond orientation, different from the first orientation, and where thecrankshaft is substantially vertically oriented.

In accordance with a further aspect of the invention, an engine operablein a first orientation and a second orientation includes a cylinderblock coupled to a crankcase and a cylinder head coupled to the cylinderblock. The cylinder head includes an intake port and an exhaust port.The intake port has a first substantially flat surface and a secondsubstantially flat surface. The intake port further includes across-section having an arch surface coupled at each end by a pair ofsubstantially parallel planar surfaces. The first substantially parallelplanar surface has a length longer than the second substantiallyparallel planar surface. The second substantially parallel planarsurface is coupled at an end opposite the arch surface to a chamfersurface at approximately a 45 degree angle. An opposite side of thechamfered surface is connected to the first substantially parallelplanar surface by a planar longitudinal surface that is opposite thearch surface.

In accordance with yet a further aspect of the invention, an engineincludes a cylinder coupled to a crankcase and a cylinder head coupledto the cylinder. The cylinder has a central axis. The cylinder headincludes an intake port and an exhaust port. The intake port includes afirst planar surface that is relatively horizontal with respect to ahorizon, and a second surface adjacent to the first planar surface. Thesecond surface has a cross section perpendicular to the central axis.The intake port further includes a third planar surface adjacent thesecond surface and opposite the first planar surface.

Various other features and advantages will be made apparent from thefollowing detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate embodiments presently contemplated for carryingout the invention.

In the drawings:

FIG. 1 is a perspective view of an internal combustion engineincorporating the present invention.

FIG. 2 is an exploded perspective view of a cylinder head of FIG. 1incorporating the present invention.

FIG. 3 is a side perspective view of the cylinder head of FIG. 2.

FIG. 4 is a side view of the cylinder head of FIG. 3.

FIG. 5 is a cross-section view taken along line 5-5 of FIG. 4.

FIG. 6 is a side view of the cylinder head of FIG. 2.

FIG. 7 is a side view of the cylinder head of FIG. 2 rotated in anexemplary orientation as implemented in the engine of FIG. 1.

FIG. 8 is a side view of the cylinder head of FIG. 2 with rockercomponents assembled therein.

FIG. 9 is a sectional view of the cylinder head of FIG. 2 showing pushrod tube holders in cross section.

FIG. 10 is a top perspective view of the cylinder head of FIG. 2.

FIG. 11 is a perspective view showing an assembled cylinder head of FIG.2 with an air guide rotated away therefrom.

FIG. 12 is a side view of the air guide of FIG. 11.

FIG. 13 is a partial sectional view of the cylinder head and air guideof FIG. 11.

FIG. 14 is a partial top view of the cylinder head and air guideconfiguration of FIG. 11.

FIG. 15 is a perspective view of a wheel driven vehicle incorporatingthe present invention.

FIG. 16 is an exemplary non-wheel driven apparatus incorporating thepresent invention.

DETAILED DESCRIPTION

Embodiments of the invention are directed to an intake port of acylinder head of an air cooled internal combustion engine; a push rodtube configuration within the cylinder head of the air cooled combustionengine; and an air guide for directing cooling air to the cylinder headof the air cooled combustion engine. The various embodiments of theinvention are incorporated into the air cooled internal combustionengine, which in turn is incorporated as a prime mover/prime powersource in any of a number of various applications, including but notlimited to, power generators, lawnmowers, power washers, recreationalvehicles, and boats, as just some examples. While embodiments of theinvention are described below, it is to be understood that suchdisclosure is not meant to be limiting but set forth examples ofimplementation of the inventions. The scope of the inventions is meantto encompass various embodiments and any suitable application in which ageneral purpose internal combustion engine can benefit from theinventions shown and described herein. It is understood that certainaspects of the inventions may equally be applicable to non-air cooledinternal combustion engines as well and such is within the scope of thepresent inventions.

Referring first to FIG. 1, an internal combustion engine 10 is anexemplary V-twin having two combustion chambers and associated pistons(not shown) within an engine block 12 having a pair of cylinder heads 14capped by rocker covers 16. The internal combustion engine 10 of FIG. 1includes decorative and functional covers 18 and 20, as well asconventional oil filter 22, pressure sensor 24, oil pan 26, drain plug28, and dip stick 30, together with the other conventional partsassociated with an internal combustion engine. A cooling source 31 drawscooling air in toward internal combustion engine 10 through covers 20.

FIG. 2 is an exploded view of cylinder head 14 having a plurality ofcooling fins 32, intake and exhaust valves 34, valve seats 36, and pushrods 38. Exploded from the upper portion of cylinder head 14 are sparkplug 40, valve guides 42, valve springs 44, rocker arms 46, bushings 48,rocker arm supports 50, spring caps 52, and slack adjusters 54. Alloperational in a conventional manner.

Cylinder head 14 includes push rod tubes 60 that are pressed fit intorespective bores 62 of cylinder head 14. Each push rod tube 60 has twooutside diameters 64, 66 that are received into bore 62 of cylinder head14 such that the smaller diameter 66 passes unobstructed through thebore 62 until the larger diameter 64 reaches the top of bore 62 to allowan even press-in fit. As is shown in further detail and will bedescribed hereinafter with respect to FIGS. 9 and 10.

FIG. 2 also shows an air guide/diverter 70 having a main diverter shield72 and a secondary air guide/diverter 74 attached thereto by fasteningwith anchors or welding. It is understood that the air guide/diverter 70could be constructed as a single unitary structure or a multi-piececonfiguration having two or more pieces. The structure and function ofthe air diverter 70 will be further described with reference to FIGS.11-14.

Referring next to FIG. 3, cylinder head 14 is shown with intake port 80in the foreground. Cylinder head 14 has a recessed rocker cavity 82having a lower surface 84 to accommodate at least a portion of the valvesprings 44 and the rocker arm assembly 90, as best shown in FIG. 8.Cylinder head 14 is then capped with rocker covers 16, as shown inFIG. 1. Referring back to FIG. 3, lower push rod tube bores 86 are shownhaving a smaller diameter than the upper push rod bores 88 as shown inFIG. 2 to accommodate the efficient press fit of push rod tubes 60therein. Accordingly, as one skilled in the art will now recognize, thepush rod tubes are wholly contained within the cylinder head from thelower surface 84 of the rocker cavity 82 down through push rod tubebores 86 extending near the lower surface of cylinder head 14, as willbe described with reference to FIG. 9.

Referring to both FIGS. 3 and 4, intake port 80 of cylinder head 14 is amodified D-shape that extends substantially evenly through cylinder head14 toward the combustion chamber, other than the standard draft requiredfor casting, which is typically and approximately 1°. The modifiedD-shape of intake port 80 comprises an arcuate surface 100 coupled tosubstantially flat side surfaces 102, 104 wherein flat side surface 102extends a length greater than that of flat side surface 104. Flat sidesurface 106 is opposite arcuate surface 100 and is joined to flat sidesurface 102 by a generally right angle 108; however, it is understoodthat the inside corner of said right angle 108 may be formed by agradual transition. Flat side surface 106 connects to flat side surface104 via a flat, substantially planar, anti-puddling surface 110 in ageneral 45 degree angle, thereby cutting off, or eliminating, what wouldbe the other 90 degree angle of a typical “D-shaped” configuration, thusforming the modified D-shaped configuration. The utility of the modifiedD-shaped configuration will be described with reference to FIG. 7.

FIG. 5 is a cross-section taken along line 5-5 of FIG. 4 and showsintake port 80 of cylinder head 14 extending inward to intake valvepassage 112. Intake port 80 is shown with the upper arcuate surface 100connected to the flat side surface 104 connected to the anti-puddlingsurface 110 via a small transition surface 114. Intake valve passage 112communicates with a combustion chamber 116. Intake port 80 extendssubstantially uniformly from an outer edge of cylinder head 14 tointersect with intake valve passage 112 and combustion chamber 116 at aninward transition region 117. The flat side surface 106 is substantiallyplanar and its cross-section is perpendicular to a central axis of acylinder bore and piston under the combustion chamber 116 or, inpreferred embodiment, parallel to the bottom surface of the cylinderhead. FIG. 5 also shows a cooling air pass-through 118 that providesadditional cooling to cooling fins 32.

Referring to FIG. 6, cylinder head 14 is shown in a side view havingpush rod tubes 60 inserted therein and shows another view of intake port80 in perspective in which arcuate surface 100 connects to thesubstantially parallel flat side surfaces 102, 104, wherein flat sidesurface 104 connects to flat side surface 106 at a substantially rightangle. The flat side surface 104 and the flat side surface 106 areconnected by the flat, substantially planar, anti-puddling surface 110via a transition surface 114.

FIG. 7 shows cylinder head 14 and intake port 80 orientated as installedon internal combustion engine 10 as shown in FIG. 1 in a horizontalcrankshaft configuration such that the flat, substantially planar,anti-puddling surface 110 is substantially horizontal. In thisconfiguration, the flat, anti-puddling surface 110 provides more surfacearea for unburned fuel to dissipate and prevent what is known in theindustry as “puddling.” As is known, “puddling” of fuel in a liquid formcan cause a pop or backfiring on re-ignition. The anti-puddling surface110, in the horizontal crankshaft orientation, reduces the occurrence ofsuch puddling in a properly tuned engine. The aforementioned internalcombustion engine 10 of FIG. 1 is also constructed to operate in avertical crankshaft position wherein flat side surface 102 issubstantially parallel with the horizon and thus becomes theanti-puddling surface. Surfaces 102, 110 are substantially planar acrossa longitudinal length of the intake port, are opposite one another inthe intake port, and are oriented approximately 45 degrees with respectto each other. It is understood that while cross-sections of theanti-puddling surface is substantially horizontal, the surface does havea slope toward the combustion chamber.

Alternatively, one skilled in the art will now readily recognize thatthe other surfaces could be used in conjunction with one another toprovide at least two anti-puddling surfaces in engine configurationorientations rotated in approximately 45 degree increments. Suchconfiguration provides for a wide implementation of an engineincorporating the present invention. This increased surface area on thehorizontal surface allows for the spreading out of fuel over a widersurface to promote higher evaporation rates, which in turn improvesatomization to improve the combustion process, and results in reducedmisfires and improves the consistency of the exhaust emissions.Additionally, the reduction and/or elimination of fuel puddling that isprovided by the present invention also reduces any periodic over-richcombustion that typically results in black exhaust emission.

FIG. 8 shows cylinder head 14 assembled with rocker arm assemblies 90mounted thereon and push rods 38 extending upward to the rocker armassemblies 90 through push rod tubes 60. Intake port 80 is shown in aside perspective view. As previously mentioned, rocker covers 16 of FIG.1 is attached over cylinder head 14 to enclose rocker arm assemblies 90.

Referring now to FIG. 9, cylinder head 14 is shown in cross sectionthrough push rod tubes 60. Push rod tubes 60 have a smaller diameter 66on a lower end and a larger diameter 64 at an upper end. With thecylinder head 14 having a larger bore 88 at the upper end and a smallerbore 86 at the lower end to allow for push rod tubes 60 to be droppedinto the passage bores 62 until resistance is met whereby the push rodtubes 60 are then pressed into place against boss stops 120. The bossstops provide affirmative seating of the push rod tubes 60 into cylinderhead 14.

Referring to FIG. 10, cylinder head 14 is shown in perspective from atop side view with push rod tube 60(a) above push rod tube passage bores62, and push rod tube 60(b) partially inserted into its respectivepassage to then be pressed firmly into place. The modified D-shapedintake port 80 is shown from the top side view perspective.

FIG. 11 shows cylinder head 14 in an assembled configuration with rockerarm assemblies 90 installed therein and push rods 38 extendingtherefrom. Air diverter 70 is shown rotated away from cylinder head 14where it is secured thereto. Air diverter 70 includes a main divertershield 72 which extends from a cooling source at a front side 121 of theengine to a back side 122 of the engine. A cooling source 31, of FIG. 1,draws air inward through engine cover 20 and air diverter 70, directssome of that cooling air into and across at least two distinct areas ofcylinder head 14. Main diverter shield 72 has a first arcuate member 124to direct cooling air over and across cooling fins 32 at a back side 122of cylinder head 14. The second arcuate member 126 directs air to andacross push rod tubes 60 and cooling fins 32 behind the push rod tubes60. The air flow is constructively divided into three paths, an internalair path shown by arrow 128 and directed by the secondary airguide/diverter 74 and second arcuate member 126, and rear air flow path130,132 being directed by main diverter shield 72 and first arcuatemember 124.

Referring to FIG. 12, these air flow channels are formed by the secondarcuate member 126 having a width 135 less than the width 137 of thefirst arcuate member 124. Air guide 70 is constructed with upper andlower lips 134, 136 to assist in retaining air flow within air guide 70.Openings 138 allow for fasteners to pass therethrough and fasten airguide 70 to cylinder head 14.

FIG. 13 is a section view showing the multiple air path/channels 128,130, 132. Air flow path 130 directs cooling air across cooling fins32(a), while air flow path 132 directs air across cooling fins 32(b).The internal air flow path 128 directs air across cooling fins 32(c)located centrally and internally within cylinder head 14.

Referring to FIG. 14, is a top section view showing air diverter 70 froma top view installed on cylinder head 14. Air guide 70 includes a firstplanar section 140 extending frontward to receive air flow thereinconnected to transition section 142 leading to longitudinally planarsection 144 and terminating at the first and second arcuate members 124,126. FIG. 14 also shows push rod tubes 60 installed in cylinder head 14with push rods 38 extending therethrough.

FIG. 15 shows an example of a wheel driven vehicle 150 powered byinternal combustion engine 10 incorporating the present inventions. Inthis case, the wheel driven vehicle is a lawnmower, but could equally beany wheel driven vehicle.

FIG. 16 shows a non-wheel driven apparatus 160, in this case a portablegenerator. The portable generator includes internal combustion engine 10driving a generator unit 162 and is just one example of a non-wheeldriven apparatus benefitting from the inventions described herein, butcould equally be applicable to any non-wheel driven apparatus, includingwatercraft.

As one skilled in the art will now readily recognize, by eliminatingpush rod passages that are usually cast into the cylinder head, andminimizing the push rod tubes, a substantial amount of the casting canbe eliminated resulting in new open areas that can be utilized foradditional cooling. The new push rod tubes of the present inventionallow for more cooling air to communicate with the combustion chamberand exhaust port.

There are two engine mounting surfaces associated with the engine of thepresent invention. FIG. 1 shows the engine is configured in thehorizontal crankshaft position with the lower end being the mountingsurface. When the engine is configured in the vertical crankshaftposition, the engine of FIG. 1 is essentially tipped back making theback side of the engine the mounting surface. In this configuration, adifferent oil pan is used and the carburetor and associated linkage aremodified but the engine configuration does not require any majormodifications.

Therefore, according to one embodiment of the invention, a cylinder headfor an internal combustion engine includes a housing having a recessdefining a top portion of a combustion chamber. The cylinder headfurther includes an intake port defined by a first channel extendingfrom the top portion of the combustion chamber to an outer end of thehousing, and an exhaust port defined by a second channel extending fromthe top portion of the combustion chamber to an outer end of thehousing. An intake valve is positioned to control communication of theintake port with the combustion chamber, and an exhaust valve ispositioned to control communication of the exhaust port with thecombustion chamber. The intake port further includes a cross-sectionhaving a modified D-shape with a single 90 degree corner. The modifiedD-shape cross-section extends substantially a length of the intake port.

In accordance with another aspect of the invention, an internalcombustion engine is configured to operate in a horizontal and avertical crankshaft configuration. The engine includes a cylinder blockhaving at least one cavity defining a combustion chamber, a crankshaftrotatably mounted to cylinder block, and at least one piston moveablyinserted in the cylinder block cavity. At least one cylinder head ismounted to the cylinder block to enclose the combustion chamber. Thecylinder head includes an intake port defined by a first passage incommunication with the combustion chamber, the intake port having firstand second flat planar surfaces and an exhaust port defined by a secondpassage in communication with the combustion chamber. An intake valve ispositioned to control communication of the intake port with thecombustion chamber and an exhaust valve is positioned to controlcommunication of the exhaust port with the combustion chamber. The firstflat surface of the intake port is substantially horizontal when theengine is positioned in a first orientation where the crankshaft issubstantially horizontally oriented, while the second flat surface ofthe intake port is substantially horizontal when the engine ispositioned in a second orientation, different from the firstorientation, and where the crankshaft is substantially verticallyoriented.

According to yet another embodiment of the invention, an engine operablein a first orientation and a second orientation includes a cylinderblock coupled to a crankcase and a cylinder head coupled to the cylinderblock. The cylinder head includes an intake port and an exhaust port.The intake port having a first substantially flat surface and a secondsubstantially flat surface. The intake port further includes across-section having an arch surface coupled at each end by a pair ofsubstantially parallel planar surfaces. A first substantially parallelplanar surface has a length longer than a second substantially parallelplanar surface. The second substantially parallel planar surface iscoupled at an end opposite the arch surface to a chamfer surface atapproximately a 45 degree angle. An opposite side of the chamferedsurface is connected to the first substantially parallel planar surfaceby a planar longitudinal surface that is opposite the arch surface.

According to yet another embodiment of the invention, an engine includesa cylinder coupled to a crankcase and a cylinder head coupled to thecylinder. The cylinder has a central axis. The cylinder head includes anintake port and an exhaust port. The intake port includes a first planarsurface that is relatively horizontal with respect to a horizon, and asecond surface adjacent to the first planar surface. The second surfacehas a cross section perpendicular to the central axis. The intake portfurther includes a third planar surface adjacent the second surface andopposite the first planar surface.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A cylinder head for an internal combustion enginecomprising: a housing having a recess defining a top portion of acombustion chamber; an intake port defined by a first channel extendingfrom the top portion of the combustion chamber to an outer end of thehousing; an exhaust port defined by a second channel extending from thetop portion of the combustion chamber to an outer end of the housing; anintake valve positioned to control communication of the intake port withthe combustion chamber; and an exhaust valve positioned to controlcommunication of the exhaust port with the combustion chamber; andwherein the intake port has a cross-section comprising a modifiedD-shape comprising a single 90 degree corner, the modified D-shapecross-section extending substantially a length of the intake port. 2.The cylinder head of claim 1 wherein the intake port comprises first andsecond flat surfaces joined to create the 90 degree corner.
 3. Thecylinder head of claim 2 wherein the intake port comprises ananti-puddling surface joined to the second flat surface to create achamfered corner thereby providing the modified D-shaped cross-sectionby eliminating a second 90 degree corner.
 4. The cylinder head of claim3 wherein the second flat surface is substantially perpendicular to acentral axis of the combustion chamber.
 5. The cylinder head of claim 4wherein the anti-puddling surface is offset 45 degrees from the secondflat surface.
 6. The cylinder head of claim 3 wherein an edge of themodified D-shaped cross-section defined by the second flat surface issubstantially perpendicular to a central axis of the combustion chamber.7. The cylinder head of claim 1 wherein the intake port has an inlet andan inward transition region, the inward transition region comprising aprotrusion in the intake port to direct the intake port to thecombustion chamber; wherein the modified D-shaped cross-section extendsfrom the intake port inlet to the inward transition region.
 8. Thecylinder head of claim 1 incorporated into one of a wheel driven vehicleand a non-wheel driven apparatus.
 9. An engine operable in a horizontaland a vertical crankshaft configuration, the engine comprising: acylinder block having at least one cavity defining a combustion chamber;a crankshaft rotatably mounted to cylinder block; at least one pistonmoveably inserted in the cylinder block cavity; at least one cylinderhead mounted to the cylinder block and enclosing the combustion chamber,the cylinder head comprising: an intake port defined by a first passagein communication with the combustion chamber, the intake port havingfirst and second flat surfaces; an exhaust port defined by a secondpassage in communication with the combustion chamber; an intake valvepositioned to control communication of the intake port with thecombustion chamber; an exhaust valve positioned to control communicationof the exhaust port with the combustion chamber; and wherein the firstflat surface of the intake port has a cross-section that issubstantially horizontal when the engine is positioned in a firstorientation where the crankshaft is substantially horizontally oriented;and wherein the second flat surface of the intake port has across-section that is substantially horizontal when the engine ispositioned in a second orientation, different from the firstorientation, and where the crankshaft is substantially verticallyoriented; and wherein the intake port further comprises an intermediateflat surface between the first and second flat surfaces.
 10. The engineof claim 9 wherein the first flat surface forms an anti-puddling surfacewhen the engine is positioned in the first orientation; and wherein thesecond flat surface forms an anti-puddling surface when the engine ispositioned in the second orientation.
 11. The engine of claim 10 whereinthe intake port further comprises a modified D-shaped cross-sectioncomprising only one 90 degree corner, the cross-section extending alength of the intake port; and wherein the intermediate flat surface andthe second flat surface are joined to create the 90 degree corner. 12.The engine of claim 11 wherein the first flat surface is joined to theintermediate flat surface to create a chamfered corner of the modifiedD-shaped cross-section spaced from the 90 degree corner by a flatsurface.
 13. The engine of claim 12 wherein the first flat surface isoffset approximately 45 degrees from the intermediate flat surface. 14.The engine of claim 11 wherein the intermediate flat surface issubstantially perpendicular to a central axis of the combustion chamber.15. The engine of claim 11 wherein an edge of the modified D-shapedcross-section defined by the intermediate flat surface is substantiallyperpendicular to a central axis of the combustion chamber.
 16. Theengine of claim 12 wherein the intake port has an inlet and a transitionregion, the transition region constructed to direct the intake port tothe combustion chamber; wherein the modified D-shaped cross-sectionextends from the intake port inlet to the transition region.
 17. Theengine of claim 12 wherein the first and second flat surfaces aresubstantially planar across a longitudinal length of the intake port andare opposite one another in the intake port.
 18. The engine of claim 9incorporated into one of a wheel driven vehicle and a non-wheel drivenapparatus.
 19. An engine operable in a first orientation and a secondorientation, the engine comprising: a cylinder block coupled to acrankcase; a cylinder head coupled to the cylinder block, the cylinderhead comprising: an intake port and an exhaust port, the intake portcomprising: a first substantially flat surface and second substantiallyflat surface; a cross-section having an arch surface coupled at each endby a pair of substantially parallel planar surfaces, a firstsubstantially parallel planar surface having a length longer than asecond substantially parallel planar surface, the second substantiallyparallel planar surface coupled at an end opposite the arch surface to achamfer surface, wherein an opposite side of the chamfered surface isconnected to the first substantially parallel planar surface by a planarlongitudinal surface that is opposite the arch surface; wherein thefirst substantially flat surface forms an anti-puddling surface when theengine is in the first orientation; and wherein the second substantiallyflat surface forms an anti-puddling surface when the engine is in thesecond orientation.
 20. The engine of claim 19 wherein a cross-sectionof the first substantially flat surface is substantially parallel to afirst mounting surface and relatively horizontal when the engine isoperated in the first orientation, and a cross-section of the secondsubstantially flat surface is substantially parallel to a secondmounting surface and relatively horizontal when the engine is operatedin the second orientation.
 21. The engine of claim 19 wherein the firstorientation is approximately 90 degrees rotated from the secondorientation.
 22. The engine of claim 19 wherein the intake port has aninlet and an intake valve passage, the shape of the cross-section of theintake port extending from the inlet to the intake valve passage.
 23. Anengine comprising: a cylinder coupled to a crankcase, the cylinderhaving a central axis; a cylinder head coupled to the cylinder, thecylinder head comprising: an intake port and an exhaust port, the intakeport comprising: a first planar surface that is relatively horizontalwith respect to a horizon; a second surface adjacent to the first planarsurface, the second surface being substantially perpendicular to thecentral axis; a third planar surface adjacent the second surface andopposite the first planar surface; and an arch surface opposite thesecond surface and coupled to one of the first planar surface and thirdplanar surface.
 24. The engine of claim 23 further comprising: a secondcylinder coupled to the crankcase in a v-twin arrangement with respectto the other cylinder, the second cylinder having a central axis; asecond cylinder head coupled to the second cylinder, the second cylinderhead comprising: an intake port and an exhaust port, the intake portcomprising: a first planar surface that is relatively horizontal withrespect to a horizon; a second surface adjacent to the first planarsurface, the second surface having a cross section perpendicular to thecentral axis; a third planar surface adjacent the second surface andopposite the first planar surface.
 25. The engine of claim 23 whereinthe third planar surface is at a 90 degree angle to the second surface.26. The engine of claim 23 wherein the second surface is offset 45degrees from the first planar surface.
 27. The engine of claim 23wherein the second surface adjacent to the first planar surface issubstantially planar.
 28. The engine of claim 9 further comprising atleast two engine mounting surfaces, a first mounting surface when theengine is configured in the horizontal crankshaft position with a lowerend of the engine being the first mounting surface, and a secondmounting surface when the engine is configured in a vertical crankshaftposition with a rear of the engine being the mounting surface.
 29. Theengine of claim 28 wherein a cross-section of the first flat surface ofthe intake port is substantially parallel to the first mounting surfaceand a cross-section of the second flat surface of the intake port issubstantially parallel to the second mounting surface.